The U.S. Air Force’s jet fighter programs — the F/A-22 and the Joint Strike Fighter — are beset by soaring costs, development delays and changing world threats that raise questions about their viability, Congress’ investigative arm said April 6.

The Government Accountability Office said in a report that the original business case for the F/A-22 has been “severely weakened” and that the original business rationale for the JSF “is unexecutable.”

The uncertainty surrounding the two fighter programs, which together require future investments of 240 billion dollars, have broad implications for the Defense Department’s program to modernize the air force’s fixed-wing tactical fighters, the report said.

They raised questions “as to whether overarching goals to reduce average aircraft age and ownership costs while maintaining force structure are now achievable,” the report said.

“Decreases in quantities (of aircraft) alone — about 30 percent since original plans — raise questions about how well the aircraft will complement our tactical air forces in the future,” it said.

The idea behind the $245 billion JSF program — the Pentagon’s costliest — was to bring down the cost per aircraft by developing a common fighter with variants for the air force, navy and marine corps. Foreign partners were brought in to add overseas sales.

:arrow: The Pentagon originally planned to acquire 3,000 of the aircraft, but has since whittled down its projected buy by 535 aircraft.

The aircraft has experienced design and weight problems that have led to increased costs and schedule delays, the report said. Moreover, the program’s customers are not sure how many aircraft they will need.

“The combination of cost overruns and quantity reductions has already diluted DOD’s (Department of Defense’s) buying power and made the original JSF business case unexecutable,” the report said.

Warning that most critical technologies will not have been proven in time for a scheduled decision in 2007 on whether to begin low-rate initial production, the GAO urged that the program take time to gain greater knowledge about the risks before proceeding.

The F/A-22, which began development in 1986 and faces a decision this month on whether to go to full production, was originally developed to vie with Soviet fighters for control of the skies.

Since the collapse of the Soviet Union, the air force has been forced to adapt the air-to-air fighter to a much different “global strike” mission.

Plans to add attack capabilities to the aircraft have driven up costs.

The Pentagon has reduced planned purchases of the fighter to fewer than 180, down from 750 in its original plans, and in December decided to halt procurement of the aircraft in 2008 rather than 2011.

“Changing threats, missions and requirements have severely weakened the original business case (for the aircraft),” the report said.

“Program milestones have slipped substantially, development costs have more than doubled and a modernization program was added,” it said.

“The recent budget decision to terminate procurement after fiscal year 2008, the prospect of additional cuts because of ceilings on program cost, and upcoming defense reviews have significant implications for the program’s viability and the future of modernization efforts,” it said.

"Maneuverability characteristics are similar to those of the F-16, with comparable instantaneous and sustained ‘High-G” performance."

F-35A

The F-35A for the U.S. Air Force matches or exceeds F-16 performance levels and goes several steps beyond with stealth, increased range on internal fuel, and advanced avionics. Operational effectiveness, supportability, and survivability are greatly enhanced as a result.

* Like the F-16, the F-35A has an internal gun and a refueling receptacle on top of the fuselage behind the canopy.

* Unlike the U.S. Air Force F-16, the aircraft is stealthy, enabling first-look, first-shot capability. It also has an internal laser designator and infrared sensors.

* Maneuverability characteristics are similar to those of the F-16, with comparable instantaneous and sustained ‘High-G” performance.

* The F-35A’s range and payload are greatly improved as well.

* The aircraft meets or exceeds all of the known service guidelines for flight performance.